Flush Valve for Gerber Toilet

I am replacing the flush valve for a 1985 Gerber toilet and would like to know what brand is recommended. I was looking at Fluidmaster and they have models 507A, 507C, and Pro 57. Anyone know what the the difference is? Thanks.

With regard to the flush valve and flapper, the consensus on here seems to be that on a generic toilet, the Korky flapper is the best. Korky makes a universal flush valve that has a wider overflow riser than most, and is twist-to-lock adjustable as to height, so you don't have to cut it, and it comes with a Korky flapper, all made in usa. You can get it at Lowe's: Korky Flush Valve

Also, you can see instructions, videos, etc. at the Korky web site. www.korky.com They also happily answer questions on their phone line in Wisconsin; super-nice folks.

The consensus isn't as great re the fill valve, but on the flush valve and flapper, I think the Korky is most-recommended.

Thanks for the quick reply. Although I really like the Korky brand fill valve (soft shutoff prevents water hammer), I would prefer a non-adjustable flush valve. It's also only available as a kit at Lowes. (I can't use the generic tank to bowl gasket, since it doesn't fit my Gerber.) That's why I was looking at the Fluidmaster.

Let me add that the only problem is a broken tank bolt that needs to be replaced. I bought a Kissler tank hardware and gasket kit for the job and figured I would replace the original flush valve while I had everything apart. Should I leave well enough alone and not replace it?

A standard Fluidmaster flush valve for 2" should work. The 1985 toilets were 3.5 gallons.
The fluidmaster kit comes with an adjustable flapper that lets you dial it up or down.

You should be able to get the thicker Gerber gasket at the hardware store too. At least the local Lowes carries them.

It's model 4020pk without the hardware. If you'd rather cut the height than twist to adjust it, part 87 or 89, depending on which flapper you like. You can try your local hardware store, or call Korky (1-800-LAVELLE) and ask 'em where you can get the part you want near you.

Doesn't sound like there's any particular reason to replace the flush valve, assuming that a standard flapper fits on it, but it's chicken soup (i.e. can't hurt) as long as you have the thing apart. One concern about the Fluidmaster flush valve is that it may have a non-standard flapper, so I personally would scratch that idea, because I would want to use a Korky flapper, and the Korky flush valve will take a generic flapper, including the Korky and Korky Plus.

Thanks for all the advice. I'll look into the Korky FV. However I'm still curious about the differences in the Fluidmaster models in my first post.

DIY Guy said:

I'm still curious about the differences in the Fluidmaster models in my first post.

Click to expand...

The 507A is black, the 507C is white. The A is at certain stores, the C is at others. Not uncommon marketing differentiation. I'm not aware of any other differences.

The Pro57 is part of their Pro series, which (from my reading) was originally-designed to give pros an opportunity to differentiate the 400A that pros were installing from the $9 part you could get yourself at Home Depot. If a pro is stocking parts, he has to charge more for it in order to cover the carry cost and, frankly, to make the total bill what he needs it to be to run his business profitably. The parts in the pro series are allegedly a little more robust, and thus give an opportunity to the pro to fairly charge more for it. In the case of the flush valve, the pro product doesn't have the "snap to install" flapper; the pro55 flapper looks a lot like a Korky, and is a "universal fit". More succinctly, Fluidmaster dominates with pros in the fill valve arena but the converse is true with respect to flappers, where Korky dominates among pros. By coming up with a flush valve that takes a universal flapper and by manufacturing a Korky-knockoff "pro" flapper, Fluidmaster's direction in the pro line is pretty clear.

See posts 9 and 10 in this thread for a typical pro opinion of the fluidmaster flapper. Redwood's opinion of fluidmaster flapper

I have a few more questions.

1) How tight do you tighten the tank bolts? I'm using the sequence "bolt - rubber washer - tank - rubber washer - metal washer - nut". FIY, the rubber washers that came with the kit are very hard.

2) What position is the flush valve mounted? The old one was at the 10 o'clock position. It looks to me like it will work better at 12 o'clock.

3) How tight do you tighten the flush valve nut and what tool do you use? I read 1/2 turn beyond hand tight.

4) There were 3 rubber U-shaped spacers between the tank and the bowl. the back one was mostly gone. Any idea what to use it it's place?

Thanks again.

(1) Um...do you have parts left over? If there are two rubber washers, then there are probably two nuts and two metal washers. If so, then it's bolt head - rubber washer - tank -metal washer - NUT, then insert this assembly into: BOWL - rubber washer - metal washer - nut. If not, then okay as you have it. As to "how tight", we don't know what model toilet you have, so we can't be too specific. In other words, on the Toto, there are three places that the bowl is supposed to contact the tank, so that you can be sure that it's level front to back and left to right; these protrusions are pretty obvious. As soon as one contacts, however, you have to stop tightening as you will otherwise crack the porcelain. So you hold the tank with one hand and try to make sure that as you tighten the bolts, the tank goes down straight and level, so that when one point of contact touches, they all touch.

(2) some diagrams: http://www.korky.com/PDF/89.pdf http://www.korky.com/PDF/4020.pdf Korky usually diagrams the overflow riser at 1pm.

(3) Correct. I use channel locks for leverage.

(4) A washer?

1) No parts left over. I used the second rubber washer on the bottom between the tank and the metal washer and nut. This is how it was previously installed and it makes sense, since the bottom of the tank has a little high spot around the holes which the rubber washer will conform to. I don't think I needed to use the rubber washer under the bowl, just the metal washer and nut. Please let me know if there's a reason not to do this.

2, 3) Thanks.

4) See photos below.

Please see the photos below. (I couldn't attach these to this post for some reason.)
https://dl.dropbox.com/u/2276678/Spacer.jpg
https://dl.dropbox.com/u/2276678/Bowl.jpg
https://dl.dropbox.com/u/2276678/Bolt.jpg
https://dl.dropbox.com/u/2276678/Tank.jpg

Okay. Don't really need that rubber washer under the tank, but okay if that's the way the manufacturer did it. The real key is not to put the metal washer under the bolt head, which lots of people do, which is completely incorrect and leads to leaks. Maybe ask a plumbing supply about the spacers? Or make do with 2? Looks like they elevate the points of contact so that it is rock-free without risking china-on-china contact.